Various forms of periodontal disease in humans are caused by oral bacteria. Oral bacteria create plaque, a sticky, colorless film of bacteria that constantly forms on the surface of teeth and may lead to periodontal diseases. Plaque, if allowed to stay on the tooth's surface will eventually lead to gingival irritation also known as gingivitis, which may be accompanied by gum swelling, bleeding and by fibrous enlargement of the gingiva.
The plaque forming bacteria create toxins which irritate the gums and result in breakdown of the attachment of gum tissues to teeth. Over time, these toxins can destroy gum tissues, allowing the infection to progress to bone loss.
Plaque that is not timely removed can combine with other materials and harden into a rough, porous deposit called calculus or scale. If the plaque and scale builds up and are not removed by professional cleaning, the gums will start to move away from the teeth. This is the start of periodontal gum disease. Pockets form between the teeth and gums. If the gums are allowed deteriorate further, the gums recede and the bone and other supporting tissues around the teeth start deteriorating and the teeth may eventually become loose.
Calculus on the tooth's surface, above the gum-line, does not contribute to periodontal diseases. However, calculus on the root surface, below the gums, makes removal of new plaque and bacteria more difficult. Unlike plaque, which can be removed by tooth brushing, calculus must be removed by a dentist or dental hygienist.
Prevention and treatment of periodontal gum disease must be based to a large extent on the control of bacterial plaque. This requires a considerable effort on the patient's part. In addition, routine professional oral hygiene techniques, through professional cleaning of the teeth and frequent reassessment of the patient's periodontal tissues to provide early detection and treatment of new or reoccurring abnormalities or of destruction of supporting periodontal tissues.
By far the most important aspect of controlling periodontal diseases is the practicing of daily oral hygiene techniques that needs to be initiated at pre-adolescence and carried on for the rest of the patient's life. Daily maintenance schedules ideally require full patient's compliance with instructions and an ideal tooth cleaning technique. Far too often, token attempts at dental bacterial control are inadequate and unsuccessful in one or more sites of the dentition leading to inflammatory changes at these sites and further loss of periodontal attachment.
Products sold for the prevention of periodontal diseases include toothpaste, mouth rinsing solutions, Manual toothbrushes, dental floss and powered toothbrushes and oral irrigators.
Chemical antibacterial agents are increasingly being used in prophylactic and therapeutic regimes for plaque-related diseases. As these agents can be rendered ineffective by the development of resistance in the target organisms there is a need to develop alternative anti-microbial treatments. Light from high-power lasers is known to be bactericidal and investigations have shown that it is effective against organisms implicated in carries and inflammatory periodontal diseases. However, the adverse effects of such light on dental hard tissues argues against its use solely as an antibacterial agent.
U.S. Pat. No. 4,784,135 to Blum et al. discloses a method for treating tooth decay, by far UV radiation generated by an argon fluoride (ArF) laser, which is based on ablative photo-decomposition of organic biological material. No staining of the material is disclosed.
U.S. Pat. No. 5,658,148 to Neuberger et al. discloses a method and a device for cleaning teeth by a low power diode laser applying the principle of photodynamic therapy. This method is based on using a photosensitizer compound. The photosensitizer compound produces singlet oxygen upon irradiation by the laser light. The singlet oxygen thus produced destroys oral bacteria.
U.S. Pat. No. 5,611,793 to Wilson discloses a method of disinfecting or sterilizing tissues, wounds or lesions of the oral cavity. The method comprises applying a photosensitizing compound to the tissues and irradiating the tissues with laser light at a wavelength absorbed by the photosensitizing compound. The helium-neon laser or the gallium aluminum arsenide diode laser used by Wilson are expensive and may not be suitable for home use.
There is a widely recognized need for a simple, inexpensive and selective method for killing oral bacteria which is suitable for home use.